Manual drywall sanders typically include a sanding element (e.g. sandpaper mounted to a support plate), and a pole mounted to the sanding element. The user can sand high walls and ceilings without using a ladder by using the pole to manipulate the sanding element over the surface to be sanded (i.e. the working surface). However, since the working surface of the wall or ceiling is above the user's head, dust and debris from the sanding process falls down onto the user, creating health issues for the user's eyes and lungs.
One proposed solution is disclosed in U.S. Pat. No. 7,104,877, which is incorporated herein by reference for all purposes. This patent discloses a dust collection bag that attaches over the sanding element to collect dust and debris. The dust collection bag is attached to the sanding element via springs. When not in use, the dust bag extends beyond the sanding element (i.e. the sanding element is retracted inside the open end of the bag). When the user presses the device against the working surface, the open end of the bag first engages the working surface, after which the bag is pushed backward by the working surface (against the force of the springs) until the sanding element becomes flush with the open end of the bag (so that both the bag and the sanding element engage with the working surface). When the device is withdrawn from the working surface, the sanding element recedes back into the open end of the bag.
There are several drawbacks to the device disclosed in the U.S. Pat. No. 7,104,877. First, if the user wants to pull back the device to see the working surface, they have to pull back the extra amount it takes for the sanding element to recede into the bag (so that the bag can be withdrawn from the working surface). Additionally, having the sanding element retract in and out of the bag, and having the bag collapse and expand each time the working surface is engaged, tends to blow the collected dust and debris out of the bag. For some surfaces, the spring loaded force of the bag on the working surface can make it difficult to effectively sand that surface (i.e. the friction of the bag on the working surface makes it difficult to operate the sanding element effectively). In practice, the device is not convenient or efficient to use.
There is a need for a dust collection mechanism for a manual sander that efficiently collects dust and debris, without unduly blocking the field of view of the working surface when the device is withdrawn therefrom.